Liberal vs. conservative blood strategies

Reducing unnecessary blood transfusions through application of restrictive transfusion strategies has become a standard of care for most patient populations. Guidelines from the majority of societies target hemodynamically stable, non-bleeding patients. Intraoperatively, the combination of anemia and blood transfusions have been shown to increase morbidity and mortality especially in high risk patients. The decision to transfuse should be based on the patient's risks of developing inadequate tissue oxygenation as opposed to a single hemoglobin trigger. Elderly patients and patients with cardiovascular disease, especially those undergoing high risk cardiac, valvular, or orthopedic procedures, have higher risks of 'inadequate oxygen supply events' when restrictive hemoglobin triggers are applied in the acute care setting. Unfortunately, the optimal intraoperative monitoring technique and critical markers of tissue hypoxia needed to guide transfusion decisions have not been identified. Perioperatively, every attempt should be made to minimize blood loss and improve the patient's tolerance to anemia, such that restrictive transfusion triggers can be utilized and transfusions avoided.